The law defines blasphemy as "publishing or uttering matter that is grossly abusive or insulting in relation to matters sacred by any religion, thereby intentionally causing outrage among a substantial number of adherents of that religion, with some defences permitted". The referendum will be held this autumn.

The advocacy group Atheist Ireland welcomed the decision today. When the law became operational, Atheist Ireland published 25 blasphemous statements on the internet to challenge it, including Richard Dawkins calling the Old Testament God a "petty, unjust, unforgiving control freak; a vindictive, bloodthirsty ethnic cleanser; ... a capriciously malevolent bully", and Björk saying "fuck the Buddhists".

Atheist Ireland chairperson Michael Nugent said: "This is a positive move by the minister. We look forward to the autumn referendum as part of our overall campaign for an ethical, secular Ireland. We ask all reasonable citizens to work together to ensure that the referendum is won.

"We reiterate that this law is both silly and dangerous: silly because it is introducing medieval canon law offence into a modern pluralist republic; and dangerous because it incites religious outrage and because its wording has already been adopted by Islamic states as part of their campaign to make blasphemy a crime internationally.

"The blasphemy reference is one of several anachronisms in our constitution that will ultimately need to be changed. Other examples are the religious oaths that prevent atheists from becoming president, or a judge, or a member of the council of state."